Kamala Harris is in a tricky spot. Her experience as a local prosecutor who worked her way up to serve as San Francisco district attorney and California attorney general will no doubt feature prominently in her presidential campaign — but Harris is also visibly eager to demonstrate she's hip to what the kids think is groovy.

Thus did the candidate find herself chatting Monday with Charlamagne tha God on his morning radio show, The Breakfast Club, a conversation in which, laughing, Harris said she smoked marijuana in college and "did inhale." Weed "gives a lot of people joy, and we need more joy," Harris added, reiterating her new support for recreational legalization.

Joy or no, Harris is right to support scaling down the drug war. But her record on this issue is not a straight leap from dank dorm room to criminal justice reform advocacy at the highest levels of government. There's a lot in between, and Harris should not be permitted to skip that part of the story.

Neither should Amy Klobuchar, Harris' fellow senator, Democratic presidential contender, and former district attorney. Like Harris, Klobuchar was not a "progressive prosecutor." She aggressively prosecuted drug offenses and generally conformed to the "tough on crime" law enforcement trends of the 1990s. Her county's prison population grew during her tenure, and she prosecuted as felonies offenses previously treated as misdemeanors.

Today, both Harris and Klobuchar cast themselves as staunch justice system reformers. Both backed the First Step Act, the limited but significant federal prison reform bill President Trump signed in late December. And though neither candidate has much in the way of position statements on her website yet, Harris' launch speech touted her history of "fighting for a more fair criminal justice system," while Klobuchar said she has advocated and "will always continue to advocate for criminal justice reform." When their full platforms do appear, it's safe to expect them to include a robust plank on reforming the justice system and cutting down the worst abuses of the war on drugs.

And that's great! But it's not what Harris and Klobuchar have believed and pursued throughout their entire public careers. That shift must not be ignored, because the detailed explanation Harris and Klobuchar owe their potential voters is precisely the difference between a thoughtful, justified evolution of views and the sort of cynical flip-flop too many politicians make when brushing themselves up for national scrutiny.

The wariness candidates have of honestly addressing a shift like this is understandable. It risks undermining the political value of years of public office, and publicly proclaiming one's own past failure of ethics, conviction, or judgment is never pleasant. It may seem safer to follow the more conventional course, recently described by my colleague Joel Mathis as "remind[ing] voters that times have changed," "bend[ing] their legislative records in a new direction," and "be[ing] forward-looking, championing policies that would protect communities while curbing police abuses and lowering high incarceration rates."

That's basically the path taken by Hillary Clinton in the last election cycle. Challenged on her record of support for policies she now repudiates — infamously epitomized in her use of the phrase "superpredator" — Clinton backed away from her old rhetoric but sidestepped any truly substantive discussion of how and why her views have changed. "We have to come to terms with some hard truths about race and justice in America," Clinton said in her major campaign speech on criminal justice topics, but she declined to use that talk to come to terms with hard truths about her own role in the injustice she decried. "We have allowed our criminal justice system to get out of balance," she said, neglecting to confront her past contributions to that very inequality.

If Harris and Klobuchar are sincere in their present commitment to reform, they cannot follow in Clinton's footsteps. They must confront the negative parts of their records in a way she would not. They should give an unflinching explanation of why their old approach was wrong and how they came to see it that way.

Scrap the thin narratives of underlying consistency and admit to a change of mind and heart. Apologize for the real damage done to those who may still be experiencing the consequences of overzealous prosecution and onerous sentencing. Stop laughing about smoking a joint in college and face up to the years of adulthood spent locking people away for nonviolent offenses.

This sort of honesty wouldn't be easy, but it would be refreshing — and it could be these former prosecutors' only chance to win the support of rightly skeptical voters whose commitment to criminal justice reform predates this campaign.